Apparatus for treating strands



Oct. 15, 1940. F, R. REEVELY APPARATUS FOR TREATING STRANDS Filed May 21, 1938 R L N r V T v P R- c v \N km NW N ml r a Patented Oct. 15, 1940 l 2,218,482

UNITED STATES PATENT OFFICE APPARATUS FOR TREATING sTaANns Frederick R. Reevely, Pointe Claire, Quebec,

' Canada, assignor to Western Electric Company,

Incorporated, New York, N. Y., a. corporation of New York Application May 21, 1938, Serial No. 209,395

6 Claims. (Cl. 91-32) This invention relates to apparatus for treatmatically compensating for the excessive extruding strands, and more particularly to apparatus ing tendency.

for coating strands, especially electrical con- Other objects and fe tures of the invention ductors, with viscous liquid or plastically pasty will appear from the fol owing detailed descripmaterials. tion of one embodiment thereof in an apparatus Insulating sheathings on electrical conductors for applying a viscous mixture ofcellulose aceare made, at the presenttime, in a multitude of tate in an acetone vehicle toa textile covered ways, some of which include the application to electrical conductor strand, taken in connection a bare or previously variously sheathed strand with the accompanying drawing in which the 10 of hardenable materials applied in liquid, semisame reference numerals are applied to identical 10 liquid, or pasty form and subsequently hardened. parts in the several figures, and in which- Thus materials in the nature of paint, enamel, Fig. l is a view in side elevation of the appavarnish, or waxes, asphalts, paraflins and the ratus with a portion of one wall broken away; like dissolved in volatile vehicles, artificial resins Fig. 2 is a broken enlarged view in horizontal hardenable by polymerization induced by heat, section of one of the twin applicator heads of and other analogous materials are used for one the apparatus; or another specific purpose. vIn many such in- Fig. 3 is a detached, further enlarged view in stances a solvent or vehicle is used which is longitudinal central section of the die supportvola-tilized to be subsequently recovered, and a ing plug shown in Fig. 2; and considerable part of the cost of the coating oper- Fig. 4 is a corresponding view thereof in end ation may arise out of the volume of material to elevation. C be recovered for subsequent re-use. Hence it is The apparatus herein disclosed comprises, desirable and may be vitally important to apply roughly, means to apply a viscous or pasty mathe raw sheathing or sheath treating material in terial to a strand combined with means to hard- F -a condition approaching dryness as nearly as en the applied material on the strand, the two may be practicable, i. e., as a liquid of high visbeing so constructed and arranged that the cosity or even a smoothly plastic paste, in order process of hardening begins immediately the that the volume of vehicle or solvent circulated coating is applied with a step of preliminarily in the process, or perhaps wasted, may be kept hardening at room temperature and subsequent low. further treatment at an elevated temperature.

An object of the present invention is to provide This app and the process to be carried out an apparatus simple in construction and rapid 'by it ge y form 110 P Of the P t and reliable in'operation, for forming a coating Vention, being f lly di o and laime n coof material, such as described above, upon a pending application Serial No. 209,396, filed May strand, in which the material maybe of a viscous 21, 1938, by the present i ve d, wo thers. or stiiily liquid nature or even a plastic paste, The apparatus generally is disclosed herein only and in which the material may be applied thickin so far as is necessary for a clear understandly "and yet uniformly. ing of the present invention and reference may With the above and other objects in view, the be had to the copend n application mentioned invention in one form may be embodied in an if necessary for the construction and function- 40 apparatus comprising an applicator head with a ing o e pparatus ge y. The Specific chamber having a strand inlet member and a m th d f app yin t coating al p acwiping die strand outlet member, and means to tised by the use of the applicator means herein supply coating material in viscous or pasty form disclosed and claimed, is disclosed andclaimed under pressure. to the chamber, the wiping die in copending application Serial No. 305,079, filed being composed of yieldable material .and so ov e 1939, by the Present lnVentOr as a formed and mounted that while the strand and division of this app ic ion adherent coating material are passing through The heart of the Paste pp ying means is a the bore of the die, the body of coating matetwin applicator de e b t Shown n and rial in the chamber has access to the rear and generally indicated by the numeral Since outer lateral surfaces of the die, whereby excesthis is W description of one side y Will sive pressure in thechamber tending to extrude suflice for both. An individual applicator com too thick a coating on the strand will simulprises a cylindrical body member 2| having a taneously tend to compress the die, thus increaschamber 22 therein,- through which passes a ing the severity of its wiping action and autostrand l9 to be coated. The strand enters the l mounted in the rear wall of the chamber, the bore of the plug being sufficiently large to pass the strand without harmful friction. The forward end of the plug extends taperingly into the chamber as at 26. Another plug 21 is mounted in the front wall of the chamber and has housed completely therein a wiper die member 28. This member or die 23 is a body of soft vulcanized rubber or similar material 24nd is given any convenient shape. The particular member or die illustrated is an ordinary soft rubber bottle stopper of suitable size. The plug 21 is recessed to fit the member 28 which is held in place in the plug by any suitable means such as the removable retainer 30. The plug 21 and retainer 30 are axially bored to pass the strand I9 with liberal clearance for both the strand and its raw coating. The die member 28 is formed with an axial bore of such size as to pass the strand [9 bearing a raw coating of predetermined desired thickness, and the member 28 acts to wipe off any superfluous thickness of coating. The twin applicators 20 may conveniently be supported, as shown, upon the upper, end of a vertical feed pipe 3| which serves to bring coating material under pressure to the chambers 22 as well as to support the twin applicators. A valve 32 mounted in the feed pipe serves to control the flow of coating material from a supply tank 33 through the pipe to the applicators. A supply of air or of some inert gas, nitrogen, carbon dioxide or other similar gas according to the nature of the coating material under pressure is fed into the upper part of the tank 33, preferably above the level of the coating material therein, through a pipe 34 from a suitable supply 35 of the compressed gas. If desired an indicating pressure gage 36 may be mounted at any convenient place and connected by a pipe 31 to the pipe 34,

A characteristic feature of the invention is that the die supporting plug 21 has the walls of its die receiving recess formed with longitudinal flutings or grooves 29,50 that the member 21 touches the lateralouter wall of the die member 28 only along the narrow edges of the ribs between the grooves 29. Thus these grooves 29, when the assembly is complete as in Fig. 2, provide chambers or recesses covering most of the outer lateral surface of the die 28, open at their rear ends to the coating material chamber 22, and closed at their front ends by the member 30.

In this manner, the pasty material under pressure in the chamber 22 flows into these grooves 29 and thus surrounds and is in contact with substantially the entire outer lateral surface of the compressible die 28. As a result, if for any reason the pressure in the chamber 22 becomes excessive and tends to form too thick a coating on the strand by forcing too much material to accom- As noted before, the present invention, as embodied in an apparatus, relates only to the applicator device per se. As herein disclosed the inchamber through an axially bored plug 24,

vention is embodied in apparatus for applying pasty coating material to a strand. It might obviously, however, be also used for liquid materials if desired, so only that the material in question be supplied under pressure to the chamber 22 or an equivalent thereof. The particular embodiment disclosed is illustrative and may be modified and departed from without departing from the spirit and scope of the invention as pointed out in and limited solely by the appended claims.

What is claimed is:

1. In an apparatus for coating strands means to apply to a strand a coating of plastic material and which means comprises a body having a chamber therein and entrance and exit apertures in the walls of the chamber to allow a strand to pass through the chamber, means to supply coating material to the chamber and to maintain the material in the chamber under pressure, and a die mounted in the exit aperture and having a bore through which a coated strand may pass and consisting of resiliently compressible material the compressible dle being so mounted that plastic coating material under pressure in the chamber may act upon the body of the die to compress the same.

2. In an apparatus for coating strands means to apply to a strand a coating of plastic material and which means comprises a body having a chamber therein and entrance and exit apertures in the walls of the chamber to allow a strand to pass through the chamber, means to supply coating material to the chamber and to maintain the material in the chamber under pressure, and a die mounted in the exit aperture and having a bore through which a coated strand may pass and consisting of soft vulcanized rubso I chamber may act upon the body of the die to compress the same. 7

3. In an apparatus for coating strands means to apply to a strand a coating of plastic material and which means comprises a body having a 4 chamber therein and entrance and exit apertures in the walls of the chamber to allow a strand to pass through the chamber, means to supply coating material to the chamber and to maintain the material in the chamber under pressure, and a die mounted in the exit aperture and having a chamber therein and entrance and exit apertures in the walls of the chamber to allow a strand to pass through-the chamber, means to supply coating material to the chamber and to maintain the material in the chamber under pressure, and a die mounted in the exit aperture and having a bore through which a coated strand may pass and consisting of soft vulcanized rubber, the compressible die being so mounted that plastic coating material under pressure in the chamber may flow around the lateral outer walls of the die to compress the same.

5. In an apparatus for coating strands with plastic material and having a chamber and means to supply plastic coating material thereto under pressure and the chamber having an exit, aperture for a strand passing through the chamber, a compressibledie mounted in the aperture and having a bore for the passage of the coated strand, the walls of the aperture wherein the die is mounted being formed with recesses communicating .with.;the chamber to allow plastic material to flow over and press on the outer lateral wall of the die.

6. In an extrusion apparatus for coating strands with plastic material, a body having an extrusion chamber therein to receive plastic coating material under pressure, and an extrusion die of compressible material to control the thickness of coating material applied to a strand passing through the chamber and the die, the die being mounted in a wall of the chamber and the chamber wall being formed with recesses communicating with the chamber to allow plastic material to flow over and press on the outer lateral wall of the die.

FREDERICK R. REEVELY. 

